1. Field of the Invention
The present invention relates to a liquid supply device and an analytical test device for analyzing a test substance in a test sample, which uses the liquid supply device.
2. Discussion of Background
Disposable analytical test devices, which are compact and capable of easily analyzing test substances in test samples, have conventionally been employed. In such conventional analytical test devices, there are analytical test devices of such a type that can elute a test substance to be detected in a test sample, using a developing liquid, and transport the test substance to a detecting portion where the test substance is detected, which are particularly used for immunoassay.
For instance, in Japanese registered design 887,647, there is disclosed an analytical test device which is used for analyzing a fluid portion of the blood such as serum in the field of clinical examination. More specifically, as shown in FIG. 1(a), a pot 2 sealed with a film 3, closing a liquid reagent therein, is incorporated in a plastics case 1. The pot 2 sealed with the film 3 is situated above an absorbent material strip 4, with the film 3 being directed downward. The analytical test device of this type is referred to as a "liquid pot upper type" test device. When this analytical test device is actually used, the pot 2 is depressed downward in such a manner that the pot 2 is moved from a position shown in FIG. 1(b) to a position shown in FIG. 1(c), so that the film 3 is ruptured by a projected portion 5 as shown in FIG. 1(c). As a result, the liquid reagent flows out of the pot 2 onto the absorbent material strip 4. The liquid reagent moves along the absorbent material strip 4 by capillary action, and a test substance contained in a test sample 6 is moved up to a detection portion 7 together with the liquid reagent, so that the result of a reaction of the test substance and the liquid reagent can be observed from above the detection portion 7.
Japanese Laid-Open Application 63-223559 (corresponding to U.S. Pat. No. 4,965,047) discloses an analytical test device as shown in FIG. 2, which comprises a plastics blister 9 holding a liquid reagent therein, provided with a sealing member 8 at a lower side of the plastics blister 9 as shown in FIG. 2. The analytical test device of this type is referred to as a "spike-rupturable vacuum type" analytical test device. When this analytical test device is actually used, the blister 9 is depressed so as to rupture the sealing member 8 with a spike 10 located within the blister 9, and the liquid reagent is caused to flow onto an absorbent material strip 11 which is disposed below the sealing member 8.
In the above-mentioned two types of the analytical test devices, the liquid reagent is applied to the fixed absorbent material strip by depressing the pot or deforming the blister, so that when the pot is depressed with too much force or the blister is abruptly deformed, a large quantity of the liquid reagent is rushed through the ruptured sealing film or member onto the absorbent material strip and is caused to flow along the absorbent material strip not only from a front side and a back side, but also from both sides of the absorbent material strip. The result is that it may occur that the liquid reagent is not sufficiently developed up to the detecting portion and does not sufficiently react with the test substance in the test sample.
In particular, in the case of the "spike-rupturable vacuum type" analytical test device, sufficient development cannot be achieved one time per four times of the tests and even when the sealing member is ruptured, it may occur that a relatively large quantity of the liquid reagent stays in the blister.
In the case of the "liquid pot upper type" test device, the reproducibility of the developing rate is poor.